Chenchong's work on net80211_ratectl

[Chenchong Qin]

Hi!

In this update, I update ieee80211_sample and complete
ieee80211_ratectl_none templete.

* rename ieee80211_rc_sample* to ieee80211_sample*. this seems to be more
harmonious.
* modify ieee80211_sample to let it use the latest net80211-ratectl
features.
* fix some errors in ieee80211_sample.
* complete the ieee80211_ratectl_none templete with newly added
net80211-ratectl functions.

You will need to add wlan_sample to sys/conf/files to make ieee80211_sample
compiled.

Thanks!

Chenchong


On Mon, Sep 16, 2013 at 5:08 PM, Chenchong Qin <qinchenchong at gmail.com>wrote:

> Hi!
>
> Yes!
>
> Here is a fresh debug log.
>
> @adrian you may received many copies of this message because I got the
> "Message body too large" limit of freebsd-wireless list. So I compress the
> log file and re-send it. Sorry to be confused. :)
>
> Thanks!
>
> Chenchong
>
>
> On Mon, Sep 16, 2013 at 4:40 PM, Adrian Chadd <adrian at freebsd.org> wrote:
>
>> Sweet!
>>
>> Does this work on your AR9227? Can you provide some example output?
>>
>>
>> -a
>>
>>
>> On 14 September 2013 21:08, Chenchong Qin <qinchenchong at gmail.com> wrote:
>>
>>> Hi!
>>>
>>> Yes, a call to ieee80211_ratectl_rc_info_set() is needed. To make other
>>> drivers work, the __init__ and __findrate__ parts also need to be adapted.
>>> When initialize the ratectl state, a cap flag must be properly set and
>>> feed to ieee80211_ratectl_init().  __findrate__ part should be repalced
>>> with our
>>> ieee80211_ratectl_rates().
>>>
>>> I've added  ieee80211_ratectl_rc_info_get() to be used to get the
>>> ieee80211_rc_info. If found the tag, use it; if not, add a new one and use
>>> it. Then we don't
>>> need to free it explicitly (the tag is freed when associated mbuf is
>>> freed) and this interface is unified to both __findrate__ and
>>> __complete__.
>>>
>>> Thanks!
>>>
>>> Chenchong
>>>
>>>
>>> On Sat, Sep 14, 2013 at 11:21 PM, Adrian Chadd <adrian at freebsd.org>wrote:
>>>
>>>> Ah, cool! I see you've only just made the other drivers compile; what's
>>>> required to make them work? i guess a call
>>>> to ieee80211_ratectl_rc_info_set() ?
>>>>
>>>> Maybe you should add a ieee80211_ratectl_rc_info_set_mbuf() helper that
>>>> does the "lookup tag; if one exists use it else use a temporary one" code
>>>> that you put in if_ath.c, if_ath_tx.c.
>>>>
>>>> Other than that, this is looking very good! thankyou!
>>>>
>>>>
>>>> -adrian
>>>>
>>>>
>>>>
>>>> On 13 September 2013 20:52, Chenchong Qin <qinchenchong at gmail.com>wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> Here is latest update. Per-device ratectl statistics is implemented in
>>>>> ath and attached when ath is attaching.
>>>>>
>>>>> Thanks!
>>>>>
>>>>> Chenchong
>>>>>
>>>>>
>>>>> On Sat, Sep 14, 2013 at 3:37 AM, Adrian Chadd <adrian at freebsd.org>wrote:
>>>>>
>>>>>> Sweet, thanks!
>>>>>>
>>>>>>
>>>>>>
>>>>>> -adrian
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 13 September 2013 09:11, Chenchong Qin <qinchenchong at gmail.com>wrote:
>>>>>>
>>>>>>> Hi!
>>>>>>>
>>>>>>> Here is some updates.
>>>>>>>
>>>>>>> Another member is added to ieee80211_rc_info to record value of the
>>>>>>> maximum aggregate size. Then, in aggregation scenario, ratectl algo can
>>>>>>> inform aggregation selection code of proper maximum aggregate size.
>>>>>>>
>>>>>>> Per-vap ratectl statistics is exported through sysctl. When
>>>>>>> ieee80211_ratectl_init() is called, this statistics api is attached. It's
>>>>>>> convenient to implement the per-device api -- just traverse the vap list
>>>>>>> and call per-vap api for each vap. But, we know that ratectl of net80211
>>>>>>> provides service to vap-granularity object, not to device directly. So, is
>>>>>>> it more suitable to implement the per-device api in device driver (i.e.
>>>>>>> attach per-device api when attaching the device)?
>>>>>>>
>>>>>>> Code will be posted later.
>>>>>>>
>>>>>>> Thanks!
>>>>>>>
>>>>>>> Chenchong
>>>>>>>
>>>>>>>
>>>>>>> On Thu, Sep 12, 2013 at 2:05 AM, Adrian Chadd <adrian at freebsd.org>wrote:
>>>>>>>
>>>>>>>> Hi,
>>>>>>>>
>>>>>>>> For now, yes, you have to assume that you won't always get a
>>>>>>>> response for a rate lookup. The buffer may be sent with NOACK set, it may
>>>>>>>> be deleted during a channel change or scan, etc.
>>>>>>>>
>>>>>>>> And yes - the rate control lookup stuff for aggregate frames is a
>>>>>>>> bit messy. It would be nice for the rate control code to return the rate
>>>>>>>> _and_ the maximum aggregate size, in case the aggregation selection wants
>>>>>>>> to cap how long frames are at the given choice.
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> -adrian
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> On 11 September 2013 10:29, Chenchong Qin <qinchenchong at gmail.com>wrote:
>>>>>>>>
>>>>>>>>> Hi!
>>>>>>>>>
>>>>>>>>> I've added some aggregation support here!
>>>>>>>>>
>>>>>>>>> At first I intend to pass subframe informations(nframes,
>>>>>>>>> per-subframe length etc.)
>>>>>>>>> to the ratectl api. But it seems to be a paradox that rate lookup
>>>>>>>>> must be performed
>>>>>>>>> before the ampdu is formed (aggregation limit based on the rate
>>>>>>>>> control decision
>>>>>>>>> is need) and subframe informations can be obtain only after the
>>>>>>>>> ampdu is formed.
>>>>>>>>> So, I add a new ieee80211_rc_info flag to ieee80211_ratectl to let
>>>>>>>>> it distinguish
>>>>>>>>> aggregation and non-aggregation scenarios. If rate lookup is
>>>>>>>>> called in an aggregation
>>>>>>>>> scenario, this flag is set. Then, ratectl algo knows that it's now
>>>>>>>>> finding rates for an
>>>>>>>>> ampdu and the framelen which records len of the first frame can be
>>>>>>>>> ignored. When
>>>>>>>>> it comes to complete period, tx status that shows number of
>>>>>>>>> subframes been sent
>>>>>>>>> and number of subframes been successfully received is passed to
>>>>>>>>> the ratectl api.
>>>>>>>>>
>>>>>>>>> I also get a question here - whether one tx that doesn't perform
>>>>>>>>> rate lookup will call
>>>>>>>>> the complete procedure?
>>>>>>>>>
>>>>>>>>> Thanks!
>>>>>>>>>
>>>>>>>>> Chenchong
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Sun, Sep 8, 2013 at 11:18 PM, Chenchong Qin <
>>>>>>>>> qinchenchong at gmail.com> wrote:
>>>>>>>>>
>>>>>>>>>> Hi!
>>>>>>>>>>
>>>>>>>>>> I've added the common ratectl state as an mbuf tag!
>>>>>>>>>>
>>>>>>>>>> After days of frustration (compile errors, boot failed, kernel
>>>>>>>>>> panics, suddenly kernel freezing...), it seems that ath now can use
>>>>>>>>>> 11n-aware net80211 ratectl api to do rate control. Attachment[0] is the
>>>>>>>>>> diff of modifications to dev/ath. Changes to net80211 is minor this time.
>>>>>>>>>> Just add some debug msgs to it. Please reference my gsoc svn repo<https://svnweb.freebsd.org/socsvn/soc2013/ccqin/head/>
>>>>>>>>>> .
>>>>>>>>>>
>>>>>>>>>> It's worth mentioning that sometimes the kernel will "freezing"
>>>>>>>>>> (it looks like all things stop working, screen is freezing, keyboard and
>>>>>>>>>> mouse are not responding) after wireless stuff start working for a while.
>>>>>>>>>> At first, I consider it caused by my modification to ath. But this strange
>>>>>>>>>> thing can also happen in a head kernel (r255382). Attachment[1] is some
>>>>>>>>>> useful messages just before it happens. By the way, I use a AR9227 device.
>>>>>>>>>>
>>>>>>>>>> And, I found that, for aggregation scenario, ath gathers tx
>>>>>>>>>> information and update the ratectl states. So, what we can do to net80211
>>>>>>>>>> to let it support aggregation?
>>>>>>>>>>
>>>>>>>>>> Thanks!
>>>>>>>>>>
>>>>>>>>>> Chenchong
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On Tue, Sep 3, 2013 at 9:29 AM, Chenchong Qin <
>>>>>>>>>> qinchenchong at gmail.com> wrote:
>>>>>>>>>>
>>>>>>>>>>> OK!
>>>>>>>>>>>
>>>>>>>>>>> Thanks! :-)
>>>>>>>>>>>
>>>>>>>>>>> Chenchong
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> On Tue, Sep 3, 2013 at 1:56 AM, Adrian Chadd <adrian at freebsd.org
>>>>>>>>>>> > wrote:
>>>>>>>>>>>
>>>>>>>>>>>> Hi!
>>>>>>>>>>>>
>>>>>>>>>>>> You can declare an mbuf tag and use that. Look at M_TXCB in
>>>>>>>>>>>> net80211 and how mbuf tags are added.
>>>>>>>>>>>>
>>>>>>>>>>>> I've long thought about adding a net80211 mbuf tag to represent
>>>>>>>>>>>> -all- of the tx related state - TX callback, rate control, rate completion,
>>>>>>>>>>>> aggregation state, retry count, etc. That way all the drivers can use it.
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>> -adrian
>>>>>>>>>>>>
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>
>